


Exponential

by madasthesea



Series: Nice work, kid [22]
Category: Spider-Man (Tom Holland Movies), The Avengers (Marvel Movies)
Genre: Emotional Hurt/Comfort, Family Dynamics, Father-Son Relationship, Fluff, Gen, Math and Science Metaphors, Not Avengers: Endgame (Movie) Compliant, Peter Parker Needs a Hug, Post-Avengers: Endgame (Movie), Tony Stark Has A Heart, Tony Stark Lives
Language: English
Status: Completed
Published: 2019-08-16
Updated: 2019-08-16
Packaged: 2020-09-01 19:42:41
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 793
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20263495
Author URL: https://archiveofourown.org/users/madasthesea/pseuds/madasthesea
Summary: “Linear algebra,” Peter repeated, leaning back against the step. His and Tony’s shoulders brushed and neither moved away.“Yeah, cause you’ve got… y=x. A straight line. One equals one, two equals two.” Peter hummed in agreement. “But then you’ve got y=x2 and it gets bigger and bigger, and suddenly one is one but two is four.”“Exponential,” Peter said





	Exponential

**Author's Note:**

> Don't be frightened by the math guys :D

“How you doing, kid?”

Peter’s head jerked up, pulled out of his thoughts. He squinted up at the Tony, the late afternoon sun silhouetting him in gold. Tony took pity on him and lowered himself onto the stair next to Peter, his knees popping.

“Uh, yeah, I’m-I’m good. Morgan’s, um, trying to surprise me or something, I don’t know. She told me to come wait here.”

Tony nodded, brushing off his hands. Bugs were buzzing around in front of them, flitting from plant to plant. Tony stared at them for a moment.

“What do you think?” Tony asked, a little too casually. “Of Morgan.”

“Oh,” Peter said, feeling like all the air’s been punched out of him. He tried to sound upbeat when he answered. “She… she’s great. Got her dad’s brains, that’s for sure.”

Tony huffed a laugh, but his brow furrowed.

“Yeah. She, uh, reminds me of you a lot, actually.”

Peter swallowed, watched a ladybug creeping across the step next to him.

“It made it… really hard, sometimes,” Tony admitted. “I’d just look at her in a certain light and all I could see was you and—”

“Mr. Stark, it’s fine.”

“—and it wasn’t fair to either of you—”

“It’s ok,” Peter insisted.

“No, it’s not. Listen,” Tony sighed, rubbing his forehead. “I don’t know how to… Ok, you know in linear algebra?”

Peter blinked. “_What?”_

Tony smiled, watching the same ladybug. “Yeah, I know, just bear with me, think back to when you were like eight or whatever—”

“I didn’t learn linear algebra at _eight_,” Peter argued, a small smile fighting to be seen.

“Sure you didn’t.”

“Says Tony-freaking-Stark,” Peter muttered.

“You’re getting me off track, Parker,” Tony said, nudging him in the ribs with his elbow. Peter took a breath. This talk seemed softer now, less like a looming obstacle in front of him. Conquerable.

“Linear algebra,” Peter repeated, leaning back against the step. His and Tony’s shoulders brushed and neither moved away.

“Yeah, cause you’ve got… y=x. A straight line. One equals one, two equals two.” Peter hummed in agreement. “But then you’ve got y=x2 and it gets bigger and bigger, and suddenly one is one but two is four.”

“Exponential,” Peter said.

“Exactly. When Pepper told me she was pregnant, I… I thought ‘I can’t love another person, I’m full up.’ Cause I had Pepper and Happy and Rhodey and you’d taken half my heart with you when you died and there wasn’t _room_,” Tony confessed.

Peter swallowed again, looking down at his feet. Tony dropped his hand on the back of Peter’s neck, rubbing lightly behind his ear with his thumb.

“But it doesn’t work like that.” Tony kept going. “When Morgan was born, I thought I’d have to give you up so that I could love her. But instead, all of a sudden, I just… did. And I still loved you. This is the cheesiest thing I’ve ever said in my life, but having kids will do that to you: It’s like my heart grew until there was room enough for both of you.”

Peter nodded numbly, trying to wrap his head around it. Tony had said he’d loved Peter more in the last two minutes than he had in the two-and-a-half years they’d known each other before and it wasn’t newbut it _was_, a little bit, and it was more than a little overwhelming.

“Peter,” Tony said, and Peter looked up out of instinct. If he’d thought it was overwhelming when Tony said that he loved him, it was nothing compared to seeing it written in every line of his face, in the light in his eyes as he looked at Peter. It took his breath away.

“You taught me how to love Morgan. Just like I love you more because I have her.”

“Exponential,” Peter whispered.

Tony smiled, the crows-feet around his eyes crinkling. “Exactly,” he said again. “So… I don’t know, maybe you hadn’t thought this at all, cause you’re a better person than me, but whatever you were thinking, about blood and family and Morgan… replacing you or something, it’s not real, ok? Cause I’ve never loved Morgan more, and I’ve never loved you more, and every time I say that for the rest of my life it’s still going to be true.”

Peter nodded, unable to speak.

Tony patted his knee and stood, back popping as he did. “Your sister’s calling for you,” he said, bending down and kissing the crown of Peter’s head. “Dinner will be ready in an hour.”

“Right,” Peter said, standing as well. Sure enough, in the distance he could hear Morgan running toward them, yelling his name in excitement for whatever adventure she’d prepared for them to embark on together

**Author's Note:**

> I kind of can't get enough of Tony assuring Peter that he's a vital member of the Stark family. 
> 
> Thanks for reading!


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